ES2275430B1 - COLORING PROCEDURE WITHOUT PIGMENTS AND CHROMATIC HOMOGENEIZATION OF ORNAMENTAL ROCKS, AND DEVICE FOR PUTTING INTO PRACTICE. - Google Patents

Abstract

The object of this Patent is a "Coloring procedure without pigments and chromatic homogenization of ornamental rocks and device for its implementation", the use of which is explicit in the statement of the invention itself. The claimed process consists essentially in the immersion or showering of the rock plates in a solution of a strong reducer, contained in a closed vessel, keeping the reaction parameters (pH, redox potential) controlled and in their optimum values by additions automatic, alternative, basifying or reducing. The device for the implementation of the procedure comprises, in the two treatment modalities, a closed tank with removable lid and provided with a stirrer, a filtering equipment for separating decanted salts and plate fragments, and measuring probes of the parameters that, acting on corresponding solenoid valves, dose the contributions of the corrective solutions to keep the reaction parameters at their optimum values.

Description

Coloring procedure without pigments and chromatic homogenization of ornamental rocks, and device for Its implementation.

Object of the invention

The object to which the invention relates to protects in this Patent, consists of a "Procedure of coloration without pigments and chromatic homogenization of rocks ornamental, and device for implementation ".

In accordance with the provisions of the Article 8-b) of the "Law Enforcement Regulations of Patents ", this application includes Claims independent for the procedure and for the device specially conceived for its implementation, since some and others "respond to the unit of invention provided for in the Article 24 of the Law and are in congruence with what is stated in the title of the invention".

As regards the dual purpose of the claimed process (coloration without pigments and chromatic homogenization), it can be specified that both they practice simultaneously, since both respond to the same chemical process, and that is why they are included in the same Registration request

Background

The use of certain rocks ornamentals (singularly, marbles) as material of decorative cladding, in cladding of wall walls, facades and, in general, of relatively large surfaces, forces to value as an aesthetic requirement both its chromatism as the uniformity of this.

Indeed, the appearance of shades aesthetically unwanted plates not only from the same quarry but even of the same block or of the same plate, or the lack of uniformity of these shades, even when they are you are aesthetically acceptable, they are characteristics chromatic that hinder or prevent the commercialization of materials in which they manifest, with the consequent loss partial or total of its value.

The economic importance of imperfections  chromatic, has moved to the search for corrective solutions of the same ones that, in the current state of the art, have consisted in the application of pigments in plate immersion baths: but these actions are not always technically applicable nor fully effective

Description of the invention

The purpose of the invention that constitutes the object of this patent consists in overcoming the natural chromatic imperfections of rock plates Ornamental, without the application of pigments, not always viable or effective, having claimed the claimed procedure attending to said priority objective and completed with the design of the device specially designed for implementation of said procedure.

The essentiality of the procedure that is the object of the Patent, focuses on the modification of the status of oxidation of dye transition metals (mainly iron), treating the surface of the plates with reagents suitable liquids, either by immersion or by shower.

To determine the most effective reagent in the treatment, three were widely considered and tested possibilities:

to)

- Complexing reagents: Its application was intended to enclose in its structure to iron to prevent its coloring at plates, forming to avoid colorless compounds.

Saturated fluoride solutions were tested sodium and calcium, ammonium phosphate, sodium citrate and others, without obtain substantial variations in the color of the samples, whereby these reagents were discarded.

b)

- Oxidizing reagents: Dichromate solutions were tested potassium, hydrogen peroxide, potassium monopersulfate, peroxide sodium and others, without fully satisfactory results.

C)

- Reductive reagents: Hypophosphite solutions were tested sodium, hydroxylamine hydrochloride, sodium azide and dithionite of sodium (Na 2 S 2 O 4), the latter being the one that gave satisfactory results.

Once the strong reducing reagent has been determined preferably usable in the claimed process, it proceeded to test the magnitudes of the parameters involved in the reaction and condition it, in order to optimize its values in order to the effectiveness of the treatment, with the following results:

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Reducer concentration: The saturated solution of sodium dithionite corresponds to 303 grams / liter However, for reasons of economy, the efficiency of solutions of lower reagent concentration, checking that the minimum effective concentration corresponded to 50 grs./litro, this being therefore the one used in the claimed procedure.

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pH of the medium: With all the pH range greater than 7, you get chromatic homogenization, the pH = 7 being very effective for discoloration

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Redox Potential: The Value Optimum of the redox potential, for decolorization at pH = 7, it is situated in the environment of -630 mV.

Regarding the industrial application of procedure, must be taken into account for the purpose of polishing the plates, that the penetration of the surface treatment does not exceeds 2 mm. and that attacks the resins used in polishing, Therefore, this application must be done before polishing the plates and after their calibration, to be able to verify that they have produced superficial wear greater than 2 mm. in said polishing operation.

Brief description of the drawings

To complement the description of the invention and facilitate the interpretation of structural characteristics and functional of the device specially designed for implementation of the claimed procedure, is accompanied as Figure 1 a scheme thereof, in which the relative disposition of the different elements that compose it, for the treatment of the plates by immersion, while in the Figure 2 schematizes the device for treatment by shower.

Description of a preferred embodiment

To clearly show nature and the Scope of the advantageous application of the "Procedure of coloration without pigments and chromatic homogenization of rocks ornamental and device for implementation "that constitutes the object of the invention, the following are described operations that make up the procedure and its sequence, as well as the structure and composition of the devices for putting in practice, referring to their respective schemes that, for representing a preferred embodiment of said devices, informatively, they should be considered in their sense more broad and not as limiters of the application and the content of the invention.

The procedure is developed by following operations, performed with the same sequence with which They describe:

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Plate calibration ornamental rock

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Dosage at concentration of 50 gr / liter of the aqueous solution of the reducer (sodium dithionite) and introduction of it in a closed tank to prevent oxidation by the atmosphere.

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Immersion of the plates in the solution contained in the tank, or alternatively, shower of the same with said solution.

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Permanent automatic control of the optimal values of the parameters involved in the reaction and condition: pH = 7 and redox potential (Eh), in the environment of -630 mV.

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Automatic correction of deviations that may occur in the optimal values of said parameters, by controlled alternative addition of solutions of basification (caustic soda) or reduction (dithionite sodium)

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Raft extraction and Drying the plates.

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Polishing them and check by re-calibrating that reducing your thickness in said operation has been less than 2 mm.

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Resin plates for its finish and for fixing iron compounds in order to avoid reversal of reactions over time.

As for the device for commissioning practice of the procedure, its structure is composed in any of the two alternative treatment modalities (immersion or shower), of the following elements:

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 One tank (1) of dimensions suitable and strong, tight reduction resistant material superiorly with removable cover and provided with:

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A stirrer (2) to homogenize the solution contained in the tank and to facilitate the drag of the grounds.

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A filtering equipment (3) of the solution, for retention and removal of salts produced in reduction reactions (mostly sodium sulfates) that tend to precipitate in the bottom of the tank, as well as fragments that can be detached from the plates.

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Probes for measuring pH (4) and redox potential Eh (5).

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Path control circuits solenoid valves (6) - (7) from the pH measuring equipment and Eh respectively, for the corrective dosage automatic basing solutions or reduction.

Claims (4)

1. Coloring procedure without pigments and chromatic homogenization of ornamental rocks, characterized in that it consists in the modification of the oxidation state of the dye transition metals, mainly iron, treating in immersion baths or showering the surface of the plates with strong reducers , preferably sodium dithionite (Na 2 S 2 O 4), which produce substantial color changes on the treated surfaces. 2. Coloring procedure without pigments and chromatic homogenization of ornamental rocks, according to Claim 1, characterized in that the preferred magnitudes of the parameters involved in the reaction are:

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Dithionite Dissolution of sodium at the concentration of 50 grams / liter.

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pH = 7, for homogenization chromatic

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Initial redox potential in the environment of -630 mV.

3. Coloring procedure without pigments and chromatic homogenization of ornamental rocks, according to the preceding claims, characterized in that their application is carried out by the following operations, carried out in the same sequence as described:

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Plate calibration ornamental rock

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Dosage at concentration of 50 gr / liter of the aqueous solution of the reducer (sodium dithionite) and introduction of it in a closed tank to prevent oxidation by the atmosphere.

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Immersion of the plates in the solution contained in the tank, or alternatively, shower of the same with said solution.

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Permanent automatic control of the optimal values of the parameters involved in the reaction and condition: pH = 7 and redox potential (Eh), in the environment of -630 mV.

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Automatic correction of deviations that may occur in the optimal values of said parameters, by controlled alternative addition of solutions of basification (caustic soda) or reduction (dithionite sodium)

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Raft extraction and Drying the plates.

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Polishing them and check by re-calibrating that reducing your thickness in said operation has been less than 2 mm.

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Resin plates for its finish and for fixing iron compounds in order to avoid reversal of reactions over time.

4. Device for implementing the method described in the preceding claims, characterized in that its structure is composed of any of the two alternative treatment modalities (immersion or shower) of the following elements:

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One tank (1) of dimensions suitable and strong, tight reduction resistant material superiorly with removable cover and provided with:

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A stirrer (2) for homogenize the solution contained in the tank.

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A filtering equipment (3) of the solution, for the retention and withdrawal of the salts produced in reduction reactions (mostly sodium sulfates) which tend to precipitate at the bottom of the tank, as well as fragments that can come off the plates.

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PH measuring probes (4) and of the redox potential Eh (5).

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Path control circuits solenoid valves (6) - (7) from the pH measuring equipment and Eh respectively, for the corrective dosage automatic basing solutions or reduction.